Hi,

I have a 2006 Mazda 5 Sport 2.0 TD.

The car has done about 130,000 and up to 112,000 it was all main dealer servicing.

Since purchasing the car at 120,000 I have given it a service myself which is not too hard on these except the cabin filter replacement is a bit tricky.

Anyway, over that last few months, the car went into limp mode without any warning. Turns out car needed a forced regen.

Rather than paying £££ to Mazda to do this, I purchased a Mazda diagnostic tool (Rotunda VCM) and performed the regeneration and cleared the codes.

What did bother me is that I didnt get any warning about the DPF so I removed the instrument cluster and noticed the DPF light had been de-soldered! I corrected this and to my horror the DPF light was flashing. I thought that the regen had failed, but looking closely at the DTCs I realised that there is a "Oil Reset" proceedure that needs to be performed within 1000km of an oil change.
I plugged my tool in and found that this reset had not happened for over 50,000km so I went ahead to try and reset it using the diagnostic software. (FYI its Ford/Mazda IDS V75.) And this brings me to my problem, the software gives a "Communication Failure" when doing an "Oil Reset".
I tried another tool, another laptop, and different software all giving the same problem.

So, my question is this - to anyone with diagnostic knowledge of these cars...

Is there a fault condition with the PCM that can cause this problem? Most other functions within IDS are OK... eg setting PCM features like seatbelt warning, tyre sizes, etc. I haven't tried module programming as I don't have any need to.

I find it very suspect that I am having this problem as well as finding the DPF light being de-soldered.

I know that I should be able to do a reset (as well as a regen) but grounding the test pin within the non MDS diagnostic connector at front of engine bay, but I want to refrain from doing this as I would like to be sure everything is being reset correctly.

Any advice greatly appreciated.

Luke